Nuclear Experiment·nucl-ex
6 papers—0 primary·6 cross-listed·reconstructed*
The lecture presents an overview of the quest for the new physics in low energy neutron phenomena. In addition to the traditional topics the quantum damping of oscillations is discussed.
Wan-Lei Guo🇨🇳 · Cheng-Jun Xia🇨🇳 · Tao Lin🇨🇳 · Zhi-Min Wang🇨🇳
We take the JUNO experiment as an example to explore nuclearites in the future large liquid scintillator detector. Comparing to the previous calculations, the visible energy of nuclearites across the liquid scintillator will be reestimated for the liquid scintillator based detector. Then the JUNO sensitivities to the nuclearite flux are presented. It is found that the JUNO projected sensitivities can be better than for the nuclearite mass GeV and initial velocity with a 20 year running. Note that the JUNO will give the most stringent limits for downgoing nuclearites with GeV and a typical galactic velocity .
Progress in neutron decay experiments requires better methods for the characterization of electron detectors. I show that for such \b{eta}-decay studies, electron time-of-flight can be used for in-situ calibration of electron detectors. Energy resolution down to a few keV can be reached for the lower part of the electron spectrum in neutron decay, where conventional calibration methods come to their limit. Novel time-of-flight methods can also be used to perform a complete experiment on electron backscattering from their detectors.
Julius Scherzinger🇸🇪 · Ramsey Al Jebali🇬🇧 · John Annand🇬🇧 · Kevin Fissum🇸🇪 · Richard Hall-Wilton🇸🇪 · Sharareh Koufigar · Nicholai Mauritzson🇸🇪 · Francesco Messi🇩🇪 · Hanno Perrey🇸🇪 · Emil Rofors🇸🇪
Untagged gamma-ray and tagged-neutron yields from 241AmBe and 238PuBe mixed-field sources have been measured. Gamma-ray spectroscopy measurements from 1 - 5 MeV were performed in an open environment using a CeBr3 detector and the same experimental conditions for both sources. The shapes of the distributions are very similar and agree well with previous data. Tagged-neutron measurements from 2 - 6 MeV were performed in a shielded environment using a NE-213 liquid-scintillator detector for the neutrons and a YAP(Ce) detector to tag the 4.44 MeV gamma-rays associated with the de-excitation of the first excited state of 12C. Again, the same experimental conditions were used for both sources. The shapes of these distributions are also very similar and agree well with previous data, each other, and the ISO recommendation. Our 238PuBe source provides approximately 2.6 times more 4.44 MeV gamma-rays and 2.4 times more neutrons over the tagged-neutron energy range, the latter in reasonable agreement with the original full-spectrum source-calibration measurements performed at the time of their acquisition.
Pierre Descouvemont🇧🇪 · L. Felipe Canto🇧🇷 · Mahir S. Hussein🇧🇷
We use a three-body Continuum Discretized Coupled Channel (CDCC) model to investigate Coulomb and nuclear effects in breakup and reaction cross sections. The breakup of the projectile is simulated by a finite number of square integrable wave functions. First we show that the scattering matrices can be split in a nuclear term, and in a Coulomb term. This decomposition is based on the Lippmann-Schwinger equation, and requires the scattering wave functions. We present two different methods to separate both effects. Then, we apply this separation to breakup and reaction cross sections of 7Li + 208Pb. For breakup, we investigate various aspects, such as the role of the alpha + t continuum, the angular-momentum distribution, and the balance between Coulomb and nuclear effects. We show that there is a large ambiguity in defining the 'Coulomb' and 'nuclear' breakup cross sections, since both techniques, although providing the same total breakup cross sections, strongly differ for the individual components. We suggest a third method which could be efficiently used to address convergence problems at large angular momentum. For reaction cross sections, interference effects are smaller, and the nuclear contribution is dominant above the Coulomb barrier. We also draw attention on different definitions of the reaction cross section which exist in the literature, and which may induce small, but significant, differences in the numerical values.
P. Agnes🇫🇷 · I. F. M. Albuquerque🇧🇷 · T. Alexander🇺🇸 · A. K. Alton🇺🇸 · D. M. Asner🇺🇸 · H. O. Back🇺🇸 · B. Baldin🇺🇸 · K. Biery🇺🇸 · V. Bocci🇮🇹 · G. Bonfini🇮🇹 · W. Bonivento🇮🇹 · M. Bossa🇮🇹 and 149 other authors
Measurements were made of scintillation light yield of alpha particles from the Rn decay chain within the DarkSide-50 liquid argon time projection chamber. The light yield was found to increase as the applied electric field increased, with alphas in a 200 V/cm electric field exhibiting a 2% increase in light yield compared to alphas in no field.
* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.